The function diagram for EFAN includes the following:
• Electronic Control Module (ECM)
• Engine Coolant Temperature (ECT) sensor
• Intake Air Temperature (IAT) sensor
• Electronic System Controller (ESC)
• Engine fan relay
Function
The EFAN control provides ON/OFF control of the engine cooling system fan. The ECM can be programmed to set and monitor limits for engine coolant temperature, intake air temperature, engine mode selection (operating or diagnostic).
EFAN is accessible with the EST. Fan on and off temperature can be programmed by technician, but the mode of operation must be done by Tech Services.
The purpose of the engine fan control is to provide the correct logic to determine when the fan should be turned on or off by energizing/deenergizing the fan drive relay. The purpose of the engine fan is to allow a higher air flow for heat exchange between the radiator and the ambient air when needed.
Engine Fan Control – This parameter indicates to the on-board electronics whether or not the truck has the
electronic engine fan control feature.
AC Fan Activation – This feature will allow fan activation through the ECM when requested from the
ESC during AC operation.
Disable – Feature is turned off at all times.
Fan On Temperature – This parameter indicates the coolant temperature that the fan will be electronically activated.
Fan Off Temperature – This parameter indicates the coolant temperature that the fan will be electronically deactivated.
